Building heating system, particularly utilizing solar and waste heat recovery

Abstract

A building heating system includes a plenum for distributing heated air and returning cool air to the heater. In accordance with this invention, additional heat pump means are provided comprising condenser or heat rejecter means positioned in the cold air plenum, heat absorber means which are preferably positioned in the attic of the building underneath the roof and/or in heat exchange relation with warmed gases from a chimney, and conduit and compressor means for providing heat transfer flow communication therebetween.

That which is claimed is: 
     
       1. In a central, forced-air building heating system which includes a plenum system for distributing heated air from a furnace in a warm air plenum, and for returning cool air to the furnace in a cold air plenum, the improvement comprising: first heat pump means comprising heat rejector means positioned to directly communicate with said cold air plenum, said heat rejector means being located upstream of an in series with said furnace, heat absorber means, and conduit and compressor means providing heat transfer flow communication therebetween, second heat pump means having heat exchange means directly communicating with said warm air plenum and located downstream of said furnace, said building defining a gable roof and rafters, and partition means attached to said rafters to define a flow plenum extending the length of said roof between gable ends plus parallel, enclosed flow channels between said rafters, said flow channels being open at both ends, the upper ends of said flow channels communicating with said flow plenum and the lower ends of said flow channels communicating with an open space below said flow plenum, said heat absorber means defining fan means, and being positioned to exchange heat with and to pass air between said flow plenum and said open space, whereby air can circulate through said flow channels, flow plenum and open space while its heat is absorbed by said heat absorber means, said building roof defining a generally sunward side and a shady side, said partition means defining said flow channels on the shady side of said roof which are longer than the flow channels defined by said partition means on the generally sunward side of said roof, whereby greater air flow passes through the flow channels under the generally sunward side of the roof than through the flow channels of the generally shady side of the roof.   
     
     
       2. The heating system of claim 1 in which said heat absorber means is positioned directly under the roof of said building. 
     
     
       3. The heating system of claim 1 in which the conduit in which heat exchange fluid passes from said heat absorber means passes through a compressor and a three-way valve prior to communicating with said heat rejecter means, said three-way valve providing selective flow communication with said second heat pump means. 
     
     
       4. In a central, forced-air building heat system which includes a plenum system for distributing heated air from a furnace in a warm air plenum, and for returning cold air to the furnace in a cold air plenum, the improvement comprising: heat pump means comprising heat rejecter means positioned to directly communicate with said cold air plenum, said heat rejecter means being located upstream of and in series with said furnace, said heat pump means also including heat exchanger means positioned adjacent the roof of said building, said roof defining rafters and partition means to define parallel, enclosed flow channels between said rafters, and means to pump air through said flow channels and then across said heat exhanger means, in which said building roof defines a generally sunward side and a shady side, said partition means defining said flow channels on the shady side of said roof being longer than the partition means defining said flow channels on the generally sunward side of said roof, whereby greater air passes through the flow channels under the generally sunward side of the roof than through the flow channels of the generally shady side of the roof.   
     
     
       5. The heating system of claim 4 in which said heat absorber means include defroster heater means for removing frozen condensation from said heat absorber means. 
     
     
       6. The building heating system of claim 4 in which second heat absorber means are positioned directly communicating with the warm air plenum and located downstream of and in series with said furnace to provide cooling of said building when said heat pump means is operated in a cooling mode, in which circumstance the heat exchanger means positioned adjacent the roof functions as the heat rejector means.